I don`t know if the problem is because I reinstalled myeclipse in another folder, but it was the last thing that I remember.

How I fixed winrar:

1. create another user on system (normal, no need to be admin)
2. there you will see that winrar context menu is back when selecting a file.
3. Go to winrar configuration and try to change the context menu just to test. It will ask admin password.
4. log off and return to your user and see if it’s back (like mine was)